[llvm] [ARM][AArch64] Reformat target parser. NFC (PR #82601)

[David Spickett via llvm-commits]

https://github.com/DavidSpickett commented:

LGTM, I've thought about this before but not had the stomach for the merge conflict it'll create. A few places are less pretty but still readable, and some more readable, so I'm happy to go with clang-format's decisions here.

@jthackray should do the final approval just to confirm that landing this now isn't going to be bad timing for their team downstream.

https://github.com/llvm/llvm-project/pull/82601